“Many bacterial pathogens produce diffusible signal factor (DSF)-type quorum sensing (QS) signals in modulation of virulence and biofilm formation. Previous work on Xanthomonas campestris showed that the RpfC/RpfG two-component system is involved in sensing and responding to DSF signals, but little is known in other microorganisms. Here we show that
in Fer-1 Burkholderia cenocepacia the DSF-family signal cis-2-dodecenoic acid (BDSF) negatively controls the intracellular cyclic dimeric guanosine monophosphate (c-di-GMP) level through a receptor protein RpfR, which contains Per/Arnt/Sim (PAS)-GGDEF-EAL domains. RpfR regulates the same phenotypes as BDSF including swarming motility, biofilm formation, and virulence. In addition, the BDSF-mutant phenotypes could be rescued by in trans expression of RpfR, or its EAL domain that functions as a c-di-GMP phosphodiesterase. BDSF is shown to bind to the PAS domain of RpfR with high affinity and stimulates its phosphodiesterase JQ-EZ-05 activity through induction of allosteric conformational changes. Our work presents a unique and widely conserved DSF-family signal receptor that directly links
the signal perception to c-di-GMP turnover in regulation of bacterial physiology.”
“Background. No specific data have been published on primary renal disease (PRD) in young adults with end-stage renal failure (ESRF). For children, congenital abnormalities of the kidney and urinary tract (CAKUT) account for 50% of renal failure and other congenital and familial disease comprise 20%. This remains true for teenage children in paediatric registries.\n\nMethods. To investigate the causes of ESRF in young adults, the UK Renal Registry data for the period 2000-2006 have been reviewed and PRD reported for all aged 18-39 years. For comparison, US Renal
Data System (USRDS) results S63845 are available for age groups 0-19, 20-29 and 30-39 years. These data are also compared with data reported by the British Association of Paediatric Nephrology (BAPN).\n\nResults. For the UK, there is a rise in the rate of ‘aetiology uncertain’ from 6% at 12-15 years to 21% by 18-21 years. This figure of 21% remains constant for the older patients in their third and fourth decades and can be increased by at least 5% by adding ‘glomerulonephritis; histologically examined but unspecified’; but these figures compare with unknown rates of 36% for the US age group 20-29 years. In the UK, for those 18-21 years, ‘glomerulonephritis’ accounts for 28%, when ‘Alport’s disease’ (6.5%) and ‘unspecified’ (4.5%) are excluded, which compares with age 12-15 of 26%. At age 18-21 years in the UK, there is a sharp decline in all CAKUT (26%) when compared with the BAPN incidence for the 12-15 age group of 45%. For those in their third decade, diabetes accounts for 14-18% of diagnoses, distorting our ability to compare data by percentage.